Valves of many types have been developed and utilized for controlling flow of virtually every kind of material capable of flowing, and vary from very simple gate valves to precision valves such as needle valves used to finely control and adjust flows in machinery, laboratory equipment, medication delivery systems, process industries, and myriad other applications.
Many critical materials are transported over long distances through pipelines, including crude oil and most petroleum products. These pipelines cross many very sensitive natural features, including rivers and streams, lakes, ocean inlets, long stretches of ocean in ocean-to-land delivery of crude oil and natural gas, bogs and marshes, and stream and aquifer watersheds. Pipeline breaches in these areas cause considerable damage to the environment, are very costly to clean up, and often impossible to completely remediate.
The present invention is intended to provide a system that can very reliably stop the flow in a pipeline if the pipeline is breached downstream of the Valve, and is intended as a component in a system utilizing negative pressure or reduced pressure in a pipeline section traversing a sensitive area, in addition to any applications in which it is desirable to provide reliable flow interruption to prevent spills or industrial mishaps.
Of special significance is the fact that the present invention provides automatic shutoff, when properly sited and installed, without any reliance on communication or energy infrastructure, making it capable of reliable function even in the event that an event requiring flow interruption (a breach or the development of a leak in a pipeline section) occurs concurrently with or because of a catastrophic event that disables communication and power infrastructures, and is readily adaptable to function in almost any conditions of terrain elevation, fluid viscosity, flow rate, pipeline size, and other variables, and is capable of sensitivity variations both in the initial engineering and construction and while in operation.